Fuse



E. F. PELLETIER ET AL Jan. 10, 1928.

FUSE

Filed Sept. 10, 1925 vision of a of the fusible link Patented Jan. 1 0,

Application fled September 10, 1888. Serial Io. 55,589.

This invention pertains to improvements in fuses and has primarily for its object the provision of a fuse with means for visibly indicatin fusing'of the fusible element.

A further ob ect resides in the provision of a fuse plug, or cartridge, combining means for indicating fusing of the link and permitting renewal of the fusible element.

'more specific object resides in the profuse of the above character, wherein upon fusing of the fucible element or link, one of the link holding elements is projected outwardly of the fuse c' thus rendering a visible indication of the b owing With the above and other objects in view, which will appear as the description proceeds, the invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described come within the and more particularly defined pended claims, changes in the herein disclosed by the apinvention may be made as scope of the claim.

In the accompanying drawing is illustrated one complete example of the physical embodiment of the present invention constructed according to the best mode so far devised for the practical application of the principles thereof.

the drawings, Figure 1 is an elevational view of a cartridge 't pe fuse constructed in accordance with t e present invention, parts being broken away and in section to more clearlyillustrate the structural features.

Figure 2 is a transverse taken on the line 2-2 of Figure 1.

Fi e 3 is a detailed link olding elements.

Figure dis a longitudinal sectional view through a plug type fuse embodying tures of the present invention.

gure 5 is a transverse section taken on the line 5-5. of Figure 4.

At the present time, where two or more are employed, considerable 'difliculty is encountered by one not familiar with the cir uits connected by the different fuses, in

determining the fuse which has blown. The present invention overcomes this disadvantage and enables mine the blown fuse due to a visible indicait being understood that such precise embodiment of the.

sectional view viewof oneof the.

a person to readily deter,- that tion actuated or released when the fusible element isblown.

Referring more particularly to- Fi of the drawing, which illustrates the inventionapplied to a cartridge type fuse, the numeral 1 indicates a shell or hollow casin formed of insulating material preferably 0 fibrous composition such as is commonly employed for insulating purposes in the electrical trade. 4

The shell I is exteriorly threaded at both ends for the reception of the ferrules 2 and 3, respectivel both of said ferrules having their outer ends exteriorlythreaded for the reception of caps 5 and 6, whichiabutthe shoulders 7 rovided by the reduced outer ends of the errules 2 and3.

Igterposed between the ferrules 3 and end cap 6 is a slotted disk 8 which receives the end of a fusible-link 9, and cooperating with the cap 6, serves to securely retain one end of the. link '9 therebetween.- The opposite end of the link 9 is carried by having its outer end slidably the end of th gure 1 mounted in e cap 5. The inner end of the plungerlO is flattened out at 11 and bent ack upon itselfto form. a book 11' .for the reception of one end of the link9.

connecting the link 9 with the plunger 10, its end is Inserted within the hook 11' whereupon the link is bent back upon the hook to form a crimp thus servin to detachably d securely bold said and As shown in Figure 1, the when in its normal position, before blow of the fusible link 9, is retracted so that its outer end is approximately flush with the end of the cap 5, the plun er being held in position by means of t e link 9 secured thereto and having its opposite end retained beivweenhthe disk 8 aifid' the ca (ith I ort e ur o projecting e punger 0 upon se i er gf or blowing of the link 9, a washer 12 issecured on the plunger, while surrounding the plunger and normally noused within the ferrule 2, is an expansible coiled sp 13 abutting the washer 12 at one end, z engaging an annular flange 14 projecting inwardly from the ferrule 2 at itfi tfi i 111 be m e orego' it w' arent upon severance riblowing of liiiis fuse 9, the plunger 10 will be released and proa plunger 10 I of the plunger 10,

jected outwardly of the cap by means of the spring 13, thus indicating the necessity of renewing the fusible element. A detailed description and explanation of 5 the manner in which the ferrules and end caps are connected by the link and plunger to close the circuit in which the fuse is employed, is avoided in that this in noway differs from the conventional types of fuses now upon the market. 7 7

Referring to that form of the invention illustrated in Figures 4 and 5 wherein the same is shown in connection with a socket or plug type fuse, the same comprises a hollow casing 15, having its inner end exteriorly threaded for' its insertion into the conventional type of socket while-its outer end is closed and provided with an opening 15 through which the visible indicating means, to be described, is projected. It will be understood that the casing 15 is formed of insulating material such as'porcelain or fibrous composition, and is provided with a reduced portion which is exteriorly threaded and has clamped thereon and conforming to its threads, a thin metal sleeve 15" which serves as a conductor.

Carried by the casing 15 and projecting into the open end thereof, is a unit 16 which serves to carry both the fusible element and the means for visibly indicating blowing of the same.

- The unit 16 comprises an end closure 17 having a reduced portion 18 projecting inwardly therefrom.

portion 18 is a nipple 19 which projects inwardly of the casing 15. Surrounding the outer end of the nipple 19 is an annular ring 20 having an inwardly projecting flange 21 disposed between the end closure 17 and the nipple 19 for the purpose of retaining one end of a fusible element 2 The annular ring 20, which is slightl tapered, is provided with a slot 23 for e reception of one end of the link 22.

Cooperating with the ring 20 and adapted to be fitted snugly thereover is a tapered ferrule 24 provided with an outwardly projecting flange 25 adapted to engage a con.-

ductor sleeve surrounding the casing 15 and to be retained between the end of said sleeve and the end closure 17; a

Cast or otherwise suitably secured within the end closnrelfl, which is formed ofinsulating material to the casing 15, is

a plug 26 which forms one-of the contact members of the fuse. The inner end of the plug 26 projects wardly'of the cap 17 and is in threaded engagement with the nipple 19, for the purpose of holding the nipple and end closure in associated position;

, Slidably mounted within the plug 26 is a plunger 27 on which is secure 'a tapered collar 28, whilea coil spring 32 the plunger and engaged between Fitted over-the reduced sleeve 19 is to prevent closed by the fuses, under the plug From the foregoing description, it will be apparent that the unit 16 serves to carry both the visible blowing indication means and the link 22. For the purpose of permitting renewal of the link 22 and setting of the indicating means, the unit 16 can be bodily removed from the casing 15 inasmuch as the same is merely inserted within the casing 15, and'loosely held in proper position by means of the longitudinal webs 31. projecting from the nipple 19 and engaging the inner wall of the casing 15. While the unit 16 is merely inserted loosely within the casing 15, it will be readily appreciated that when the casin 15 is screwed into the conventional fuse socket, the conductor 26,.securedwithin the end closure 17 and the nipple 19, will engage the bottom of the socket and serve to hold the unit 16 securely within the casing 15.

In the operation of the plug, as illustrated in Figure 4, the parts are shown in their normal position wherein the link 22, having one end tightly secured'between the ring 20 and ferrule 24, and its opposite end between the collar 28 and the ferrule 30, serves to hold the plunger in retracted position against a spring 32 and that, upon fusing of the link 22, the plunger will be released and projected by meansof the spring thus allowing the insulating sleeve 29 to serve as a visible indication that the fusible element has been blown. In this connection, it will be noted that the purpose of the insulating the possibility of direct contact with the plunger when the same is projected, although when projected, the plunger 29 would, under practically all conditions, be disconnected from the circuit some conditions, 115 such as where a long link is used, one'han dling the fuse might be otherwise subject to shock were direct contact with the plunger ermissible. i

In order to renew the fusible member and again set the indicating means, the entire unit '16 is withdrawn 'fromthe casing 15 and the ferrules 24' and 30 are removed to permit insertion of the ends of the link 22. The ferrules are then forced back into their respective positions, as shown in Figure 4, which serves to securely retain and holdthe sleeve 29 in retracted position indicating that thefuse is ready for operation.-

While: the present invention has been shown in two forms, it will be quite apparent portion pro'ecting through the aperture that the principles of the invention are emthrough sai casing, a spring urging the bodied in both, namely, means whereby the movable member outwardly, and a fusible fusible element may be renewed and one of link. removably held between said movable 8 the link retaining members being adapted for member and the base of said unit, said link projection from the casing to visibly indicate being connected to the central conductor of blowing of the fusible element. i said unit-and to said metal ferrule, said mov- We claim: 7 able member having a clamp for clamping A fuse comprising a plug-like member one end of said fusible link. v10 open at its inner end and having an apere In testimony that we claim the foregoing ture through its outer end, a threaded metal we have hereunto set our hands at-St. J osferrule surrounding the inner end 'of said e h' in the county of Berrien and State of casing, a removable unit normally ositioned li ichigan. within said casing and having a ase provided with a central conductor, a movable EMMET F. PELLETIER. member carried by said unit and having a W ALTER BANDLOW. 

